USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Pecan is a major crop in Lower Rio Grande Basin. Currently there exist about 30,000 acres (12,000 ha) of pecan orchards at various stages of growth which consumes about 40 percent of irrigation water in the area. Crop evapotranspiration (ET) varies with age, soil type and method of management. The ET variation and lack of information on optimum crop ET result in significant variation in productivity and income. In order to maximize the returns from limited water resources, there is a need for a better understanding of pecan optimum ET. ET was measured using three eddy covariance flux towers, which were installed in selected fields in the irrigated area. This paper describes a process where remotely sensed data from ASTER were combined with ground level information to estimate pecan ET and crop coefficient (Kc) throughout the area. The measured cumulative annual pecan ET were determined as 1470 mm (4.82 ft) compared to a predicted value of 1415 mm (4.68 ft) using the remote sensing model. Regression summary for measured ET as depended variable resulted in Standard Error of Estimate (SEE) of 0.86 mm/day and adjusted R2 of 0.9045 for 363 days of measured data

A typology of different development and testing options for symbolic regression modelling of measured and calculated datasets

AbstractData-driven modelling is used to develop two alternative types of predictive environmental model: a simulator, a model of a real-world process developed from either a conceptual understanding of physical relations and/or using measured records, and an emulator, an imitator of some other model developed on predicted outputs calculated by that source model. A simple four-way typology called Emulation Simulation Typology (EST) is proposed that distinguishes between (i) model type and (ii) different uses of model development period and model test period datasets. To address the question of to what extent simulator and emulator solutions might be considered interchangeable i.e. provide similar levels of output accuracy when tested on data different from that used in their development, a pair of counterpart pan evaporation models was created using symbolic regression. Each model type delivered similar levels of predictive skill to that other of published solutions. Input–output sensitivity analysis of the two different model types likewise confirmed two very similar underlying response functions. This study demonstrates that the type and quality of data on which a model is tested, has a greater influence on model accuracy assessment, than the type and quality of data on which a model is developed, providing that the development record is sufficiently representative of the conceptual underpinnings of the system being examined. Thus, previously reported substantial disparities occurring in goodness-of-fit statistics for pan evaporation models are most likely explained by the use of either measured or calculated data to test particular models, where lower scores do not necessarily represent major deficiencies in the solution itself

USCID fourth international conference

Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Elephant Butte Reservoir with an estimated surface area of 40,000 acres at full capacity is considered a major component of the Rio Grande hydrology. Understanding evaporative loss from the reservoir is needed for management and distribution of the Rio Grande water among various users. An eddy covariance tower is currently measuring the evaporation rate in a localized area of the reservoir. However, evaporation is highly variable across the Reservoir's water surface. This paper describes a methodology to account for spatial and temporal variability of the evaporation from reservoir using a combination of remote sensing and ground measurement

Using the Hydraulic Properties of Zeolite to Grow Desert Willow—A Case Study to Rehabilitate Riparian Areas of Semi-Arid Environments

Plants in riparian areas are well known for their beneficial functions such as providing biodiverse habitats, maintaining water quality, and stabilizing streambanks. However, riparian plants are declining in semi-arid environments due to long-term drought, a decline in groundwater table, and an increase in soil salinity. A new technique using clinoptilolite zeolite (CZ) as a wicking material with minimum artificial irrigation to grow desert willow [Chilopsis linearis (Cav.) Sweet] under field conditions is introduced; desert willow is native to riparian regions of the southwestern United States. For this study’s experiment, desert willow seedlings were planted in boreholes filled with clinoptilolite zeolite (CZ) as a substrate and in situ riparian sandy loam soil (RS) as a control. The boreholes extended to the groundwater table at two distinctive depths, shallow (avg. depth = 1.21 m) and deep (avg. depth = 2.14 m). The plants’ viability was then assessed by measuring their midday water potential (Ψmd) as an indicator of water stress. There was no significant difference in Ψmd (p > 0.05) between the plants grown in CZ and RS (mean Ψmd = −0.91 vs. −0.81 MPa) where the groundwater was shallow and a significant difference (mean Ψmd = −0.75 vs. −2.03 MPa) where the groundwater was deep. The proposed method is promising as an alternative method for growing desert willow or other plants for riparian rehabilitation with no artificial irrigation. However, its effectiveness depends on groundwater being accessible at the base of the boreholes used for planting

Emerging challenges and opportunities for irrigation managers

Presented at Emerging challenges and opportunities for irrigation managers: energy, efficiency and infrastructure: a USCID water management conference held on April 26-29, 2011 in Albuquerque, New Mexico.Includes bibliographical references.Numerous rapidly growing urban areas in the western United States are located in irrigated river valleys. Agricultural irrigation in these communities is being affected by urbanization, and the characteristics and objectives of the irrigator population are also changing. New Mexico's Middle Rio Grande Conservancy District (MRGCD) encompasses the rapidly growing Albuquerque metropolitan area. The South Valley is one of the state's oldest traditional agricultural communities, and is located on the southern fringe of Albuquerque within the MRGCD. South Valley irrigated agriculture is in a state of transition, and many lands that were previously used to produce a diverse mix of fruits, vegetables, grains and forages have been converted into commercial and residential development. A few relatively large farms continue to operate in the area; however, hundreds of small or micro-scale irrigated properties are located in the South Valley. These small rural-residential properties predominately apply MRGCD irrigation water to hay and pasture. Little is known about agronomic, irrigation, or marketing practices on South Valley micro-farms, as well as the economic outcomes or impacts of irrigation water use. A team of New Mexico State University researchers is currently surveying MRGCD irrigators, measuring alfalfa consumptive use, and attempting to quantify the economic impact of South Valley irrigated agriculture

Assessing Satellite-Derived OpenET Platform Evapotranspiration of Mature Pecan Orchard in the Mesilla Valley, New Mexico

Pecan is a major crop in the Mesilla Valley, New Mexico. Due to prolonged droughts, growers face challenges related to water shortages. Therefore, irrigation management is crucial for farmers. Advancements in satellite-derived evapotranspiration (ET) models and accessibility to data from web-based platforms like OpenET provide farmers with new tools to improve crop irrigation management. This study evaluates the evapotranspiration (ET) of a mature pecan orchard using OpenET platform data generated by six satellite-based models and their ensemble. The ET values obtained from the platform were compared with the ET values obtained from the eddy covariance (ETec) method from 2017 to 2021. The six models assessed included Google Earth Engine implementation of the Surface Energy Balance Algorithm for Land (geeSEBAL), Google Earth Engine implemonthsmentation of the Mapping Evapotranspiration at High Resolution with Internalized Calibration (eeMETRIC) model, Operational Simplified Surface Energy Balance (SSEBop), Satellite Irrigation Management Support (SIMS), Priestley–Taylor Jet Propulsion Laboratory (PT-JPL), and Atmosphere–Land Exchange Inverse and associated flux disaggregation technique (ALEXI/DisALEXI). The average growing season ET of mature pecan estimated from April to October of 2017 to 2021 by geeSEBAL, eeMETRIC, SSEBop, SIMS, PT-JPL, ALEXI/DisALEXI, and the ensemble were 1061, 1230, 1232, 1176, 1040, 1016, and 1130 mm, respectively, and 1108 mm by ETec. Overall, the ensemble model-based monthly ET of mature pecan during the growing season was relatively close to the ETec (R2 of 0.9477) with a 2% mean relative difference (MRD) and standard error of estimate (SEE) of 15 mm/month for the five years (N = 60 months). The high agreement of the OpenET ensemble of the six satellite-derived models’ estimates of mature pecan ET with the ETec demonstrates the utility of this promising approach to enhance the reliability of remote sensing-based ET data for agricultural and water resource management

Cancer Epidemiology and Control in the Arab World - Past, Present and Future

The Arab world, stretching from Lebanon and Syria in the north, through to Morocco in the west, Yemen in the south and Iraq in the east, is the home of more than 300 million people. Cancer is already a major problem and the lifestyle changes underlying the markedly increasing rates for diabetes suggest that the burden of neoplasia will only become heavier over time, especially with increasing obesity and aging of what are now still youthful populations. The age-distributions of the affected patients in fact might also indicate cohort effects in many cases. There are a number of active registries in the region and population-based data are now available for a considerable number of countries. A body of Arab scientists are also contributing to epidemiological research into the causes of cancer and how to develop effective control programs. The present review covers the relevant PubMed literature and cancer incidence data from various sources, highlighting similarities and variation in the different cancer types, with attempts to explain disparities with reference to possible environmental factors. In males, the predominant cancers vary, with lung, urinary bladder or liver in first place, while for females throughout the region breast cancer is the greatest problem. In both sexes, non-Hodgkins lymphomas and leukemias are relatively frequent, along with thyroid cancer in certain female populations. Adenocarcinomas of the breast, prostate and colorectum appear to be increasing. Coordination of activities within the Arab world could bring major benefits to cancer control in the eastern Mediterranean region